胰岛素如同打开细胞大门的钥匙

Insulin Acts a Key to Open Up Cell to Receive Glucose

 

 

胰岛素(INSULIN)影响碳水化合物、蛋白质和脂肪代谢。你的身体将这些营养物质分解成糖分子、氨基酸分子和脂质分子。身体也可以储存和重组这些分子,形成更复杂的形式。胰岛素会导致这些营养物质的储存,而另一种叫做胰高血糖素(GLUCAGON))的胰腺激素会释放这些营养物质。

 

 

 

胰岛素与你身体的谨慎平衡有关,使你的血糖水平保持在正常范围内。简而言之:

如果你的血糖过高:胰腺释放胰岛素,帮助细胞从血液中吸收葡萄糖,从而降低血糖水平。

如果你的血糖很低:胰腺释放胰高血糖素,帮助肝脏释放储存在肝脏中的葡萄糖,从而提高血糖水平。

 

 

 

当大多数食物被消耗时,血糖水平会升高,但是随着碳水化合物的摄入,血糖水平会升高得更快更剧烈。消化系统从食物中释放葡萄糖,葡萄糖分子被血液吸收。上升的葡萄糖水平表明胰腺分泌胰岛素以清除血液中的葡萄糖。胰岛素与细胞表面的胰岛素受体结合,作为打开细胞大门让葡萄糖进入的钥匙。

 

 

 

几乎所有的组织都有胰岛素受体,包括肌肉细胞和脂肪细胞。

 

胰岛素受体有两个主要的组成部分——外部和内部部分。外部部分延伸到细胞外并与胰岛素结合。当这种情况发生时,受体的内部部分会在细胞内发出信号,让葡萄糖转运体运动到表面并接收葡萄糖。当血糖和胰岛素水平降低时,受体就会空出来,葡萄糖转运体就会回到细胞中。

 

 

 

 

How Insulin Works

Insulin affects carbohydrate, protein, and fat metabolism. Your body breaks these nutrients down into sugar molecules, amino acid molecules, and lipid molecules. The body can also store and reassemble these molecules into more complex forms. Insulin causes the storage of these nutrients, while another pancreatic hormone called glucagon releases them from storage.

 

Insulin is involved in your body's careful balancing act to keep your blood sugar levels within a normal range. In simple terms:

 

 

If your blood sugar is high: The pancreas releases insulin to help cells absorb glucose from the bloodstream to lower blood sugar levels.

If your blood sugar is low: The pancreas releases glucagon to help the liver release stored glucose into the bloodstream to raise blood sugar levels.

 

Blood sugar levels rise when most foods are consumed, but they rise more rapidly and drastically with carbohydrates. The digestive system releases glucose from foods and the glucose molecules are absorbed into the bloodstream. The rising glucose levels signal the pancreas to secrete insulin to clear out glucose from the bloodstream. Insulin binds with insulin receptors on cell surfaces and acts as a key to open up the cells to receive glucose. Insulin receptors are on almost all tissues, including muscle cells and fat cells.

 

 

Insulin receptors have two main components—the exterior and interior portions. The exterior portion extends outside the cell and binds with insulin. When this happens, the interior part of the receptor sends out a signal inside the cell for glucose transporters to mobilize to the surface and receive glucose. As blood sugar and insulin levels decrease, the receptors empty and the glucose transporters go back into the cell.

 

How Insulin Works in the Body  https://www.verywellhealth.com/how-insulin-works-in-the-body-1087716